Subject: Re: Again: Booting a Vax-Server 3100 with NetBSD-1.4
To: Jason Thorpe <firstname.lastname@example.org>
From: Johnny Billquist <bqt@Update.UU.SE>
Date: 06/28/1999 20:38:29
On Wed, 23 Jun 1999, Jason Thorpe wrote:
> On Wed, 23 Jun 1999 10:16:27 +0100 (BST)
> Andrew Phillips <email@example.com> wrote:
> > Johnny Billquist Wrote:
> > >
> > >Obscure note on the pdp-11: it's actually middle-endian. :-)
> > >A 32-bit integer is stored as 3412.
> > >(Using the FP-11 for 32-bit stuff)
> > >
> > There's not many machines that have an Endian type
> > defined specifically for them.
> Part of the PDP-11's weirdness here is the fact that you're talking
> about something larger than a wordsize. Going strictly on wordsize,
> the PDP-11 is little endian (1,2).
> However, for whatever reason, the most significant word of a longword
> was stored first in memory; I don't remember if that was a software
> convention, or a hardware thing.
It was hardware. The FP-11 stored data that way. But to make
things even more interesting, some software actually stored longwords as
1234, neccecetating a word swap before using the hardware.
(Don't remember the software offhand...)
Johnny Billquist || "I'm on a bus
|| on a psychedelic trip
email: firstname.lastname@example.org || Reading murder books
pdp is alive! || tryin' to stay hip" - B. Idol